Multilayer laue lens

Abstract

The application discloses a multilayer film laue lens, which comprises a plurality of functional film layers arranged in a stack, each of the functional film layers is arranged obliquely relative to a light transmission axis of the multilayer film laue lens, the functional film layer comprises an absorption layer and a spacer layer arranged in a stack, and the absorption layer and the spacer layer of adjacent functional film layers are arranged alternately; and a gradient of the functional film layer in at least part of a layer number interval changes linearly. According to the above scheme, the gradient of the functional film layer in at least part of the layer number interval changes linearly, that is, the gradient increment of adjacent functional film layers is constant, so that only the functional film layer with the linear gradient needs to be uniformly calibrated, that is, a uniform preparation process and parameters are adopted when the layers are prepared, and therefore, the preparation difficulty of the wedge-shaped multilayer film laue lens is reduced.

Description

Technical Field

[0001] This invention generally relates to the field of hard X-ray focusing optical elements, and specifically to a multilayer Laue lens. Background Technology

[0002] X-ray microscopy can characterize the density, elemental composition, valence state, strain, morphology, magnetism, atomic and electronic structure, and dynamics of complex materials at the nanoscale, making it an important research tool in fields such as biology, medicine, materials science, physics, and chemistry. The X-ray focusing size directly affects the characterization capability of X-ray microscopes. Currently, multilayer Laue lenses (MLLs) are the optical elements with the least difficulty in focusing X-rays smaller than 10 nm.

[0003] Multilayer Laue lenses can be structurally divided into tilted and wedge-shaped types. Compared to tilted lenses, wedge-shaped lenses have higher diffraction efficiency and larger numerical aperture, enabling higher resolution and more efficient focusing. However, the fabrication process of wedge-shaped multilayer Laue lenses is quite difficult because they consist of nearly ten thousand gradient films, each with a different gradient that varies polynomially. Therefore, to fabricate an ideal wedge-shaped multilayer Laue lens, it is necessary to calibrate nearly ten thousand different gradient films, which is practically impossible in terms of manufacturing technology. Summary of the Invention

[0004] This application aims to provide a multilayer Laue lens, which at least reduces the difficulty of fabricating wedge-shaped multilayer Laue lenses.

[0005] This invention provides a multilayer Laue lens, comprising multiple functional layers stacked together, each functional layer being inclined relative to the transmission axis of the multilayer Laue lens. Each functional layer includes stacked absorption layers and spacer layers, with the absorption layers and spacer layers of adjacent functional layers alternating. The gradient of the functional layers varies linearly within at least a portion of the layer count range.

[0006] The gradients of each of the functional membrane layers within at least a certain number of layers are obtained in the following manner:

[0007] ;

[0008] ;

[0009] ;

[0010] For each of the functional membrane layers within a predetermined number of layers Perform linear fitting to obtain the gradient;

[0011] in, The number of functional film layers in the multilayer Laue lens from thickest to thinnest direction. For the first The position radius of the functional film layer described above. The operating wavelength of the multilayer Laue lens is [not specified]. The focal length of the multilayer Laue lens is... For the first The thickness of the functional film layer described above, , where represents the theoretical gradient value of each of the functional membranes that are not linearly fitted.

[0012] As an alternative implementation, the absorber layer and the spacer layer in the same functional membrane layer have the same thickness.

[0013] As an implementation method, the absorber layer is made of at least one of WSi2 and Nb, and the spacer layer is made of at least one of Si and Al.

[0014] As an implementation method, the maximum number N of the functional films of the multilayer Laue lens is determined according to the following relationship;

[0015] ;

[0016] in, The thickness of the Nth functional film layer; The thickness of the outermost absorption layer or the spacer layer.

[0017] As a possible implementation, for more than 70% of all said functional film layers... Perform linear fitting.

[0018] As one possible approach, the functional film layer from the predetermined layer to the outermost functional film layer... Perform linear fitting.

[0019] As a possible implementation, for 80% of all said functional membrane layers... Perform linear fitting.

[0020] The above scheme reduces the difficulty of fabricating wedge-shaped multilayer Laue lenses because the gradient of the functional film layers changes linearly within at least a portion of the layer range, meaning that the gradient increment of adjacent functional film layers is constant. This means that only the functional film layers with linearly changing gradients need to be uniformly calibrated, i.e., uniform fabrication processes and parameters are used when these layers are fabricated. Attached Figure Description

[0021] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figure 1 This is a schematic diagram of the structure of a multilayer Laue lens provided in an embodiment of the present invention;

[0023] Figure 2 The diagram compares the relationship between the gradient of each functional film layer and the number of functional film layers in a multilayer Laue lens with a linear gradient of the functional film layer in the present invention, and a wedge-shaped multilayer Laue lens with a polynomial relationship of the gradient of the functional film layer.

[0024] Figure 3 A one-dimensional focusing comparison diagram of a multilayer Laue lens with a linear gradient of the functional film layer in the present invention and a wedge-shaped multilayer Laue lens with a polynomial gradient of the functional film layer.

[0025] Figure 4 The diagram shows a comparison of the intensity distribution near the focal point when focusing: a multilayer Laue lens with a linear gradient of the functional film layer and a wedge-shaped multilayer Laue lens with a polynomial relationship to the gradient of the functional film layer. Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, the present invention provides a multilayer Laue lens, which is, for example but not limited to, a wedge-shaped multilayer Laue lens, comprising multiple functional film layers 1 stacked together. Each functional film layer 1 is inclined relative to the light transmission axis of the multilayer Laue lens. Each functional film layer 1 includes an absorption layer 11 and a spacer layer 12 stacked together. The absorption layer 11 and the spacer layer 12 of adjacent functional film layers 1 are alternately arranged. The gradient of the functional film layers 1 within at least a certain number of layers varies linearly.

[0029] The gradient mentioned here can be considered as the tilt angle θ of the functional film layer 1 relative to the light transmission axis of the multilayer Laue lens.

[0030] in, Figure 1The Z-axis is the transmission axis of this multilayer Laue lens.

[0031] For example, the gradient of the nth functional membrane layer 1 is m; the gradient of the (n-1)th functional membrane layer 1 is m+i, and the gradient of the (n+1)th functional membrane layer 1 is mi; the gradient of the (n-2)th functional membrane layer 1 is m+2i, and the gradient of the (n+2)th functional membrane layer 1 is m-2i. The specific values ​​of m and i can be determined according to the actual situation.

[0032] For example, the multilayer Laue lens can be deposited sequentially and alternately on the substrate 2, wherein the absorption layer 11 and the spacer layer 12 can be deposited first, followed by the deposition of the spacer layer 12, and then a thinner layer of the absorption layer 11 and the spacer layer 12, and so on, until a predetermined number of absorption layers 11 and spacer layers 12 are deposited; or the spacer layer 12 can be deposited first, followed by the deposition of the absorption layer 11, and then a thinner layer of the spacer layer 12 and the absorption layer 11, and so on, until a predetermined number of absorption layers 11 and spacer layers 12 are deposited. The deposition process of the absorber layer 11 and the spacer layer 12 can be any one of the following: Chemical Vapor Deposition (CVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), Physical Vapor Deposition (PVD), Pulsed Laser Deposition (PLD), Atomic Layer Deposition (ALD), and Plasma Enhanced Atomic Layer Deposition (PEALD).

[0033] The above solution, since the gradient of the functional film layer 1 within at least a portion of the layer range changes linearly, that is, the gradient increment of adjacent functional film layers 1 is constant, only the functional film layers 1 with linearly changing gradients need to be uniformly calibrated. That is, when these layers are fabricated, uniform fabrication processes and parameters are used. Therefore, the fabrication difficulty of the wedge-shaped multilayer Laue lens is reduced. In other words, the solution of this application is an optimization of the existing wedge-shaped multilayer Laue lens, optimizing the gradient of adjacent functional film layers in the prior art, which has a polynomial relationship, into the solution of this application, where the gradient of at least a portion of adjacent functional film layers 1 changes linearly, thereby reducing the processing difficulty and further reducing the manufacturing cost.

[0034] As an alternative approach, to further reduce the fabrication difficulty, the absorber layer 11 and the spacer layer 12 of the same thickness can be deposited in the same functional film layer 1, that is, the absorber layer 11 and the spacer layer 12 in the same functional film layer 1 have the same thickness.

[0035] As an implementation, the material of the absorber layer 11 includes at least one of WSi2 and Nb, and the material of the spacer layer 12 includes at least one of Si and Al.

[0036] For example, in one example, the absorber layer 11 is made of WSi2 and the spacer layer 12 is made of Si.

[0037] As an implementation method, the gradient of each of the functional membrane layers 1 within at least a certain number of layers is obtained in the following manner:

[0038] ;

[0039] ;

[0040] ;

[0041] For each of the functional film layers 1 within the predetermined number of layers range Perform linear fitting to obtain the gradient;

[0042] like Figure 2 As shown, the calculated functional membrane layer 1 has the following properties: The theoretical gradient values ​​of each of the functional membrane layers 1 that are not linearly fitted exhibit a polynomial relationship in curve B, meaning that at this point... Same as in the prior art, then for A linear fit is performed to obtain the gradient of the linear change in this application, as shown by line A.

[0043] in, The number of functional film layers 1 in the multilayer Laue lens from the thickest to the thinnest direction (or it can be considered as the number of functional film layers 1 from the substrate 2 to the edge of the multilayer Laue lens). For the first The positional distance of the functional membrane layer 1 described above (i.e.) Figure 1 (Dimensions of the functional film layer 1 from substrate 2 to the nth layer in the X-axis direction). The operating wavelength of the multilayer Laue lens is [not specified]. The focal length of the multilayer Laue lens is... For the first The thickness of the functional film layer 1 described above, The theoretical gradient values ​​for each of the functional membrane layers 1 that are not linearly fitted.

[0044] The thickness mentioned in this article is only used to distinguish the thickness relationship of different film layers, and does not involve their specific thickness values.

[0045] The theoretical gradient value here refers to the polynomial gradient of the multilayer Laue lens before linear fitting.

[0046] As an implementation method, the maximum number N of the functional film layer 1 of the multilayer Laue lens is determined according to the following relationship;

[0047] ;

[0048] in, The thickness of the Nth functional film layer 1; The thickness is the outermost absorption layer 11 or the spacer layer 12.

[0049] As a possible implementation, for more than 70% of the aforementioned functional film layers 1, the... Perform linear fitting.

[0050] As one possible approach, the functional film layer 1 from the predetermined layer to the outermost functional film layer 1... Perform linear fitting.

[0051] The specific layer from which linear fitting begins can be determined based on the actual situation; there is no unique limitation on this here.

[0052] For example, but not limited to, the multilayer Laue lens has 13,750 functional film layers 1, which can control the functional film layers 1 from the 3000th layer to the 13,750th layer. Perform linear fitting.

[0053] The number of functional layers 1 in a multilayer Laue lens can be determined based on the incident light energy, focusing resolution, focal length, total film thickness (the thickness of all absorption layers 11 and spacer layers 12), and the thickness of the outermost layer (either the outermost absorption layer 11 or the outermost spacer layer 12). For example, if the incident light energy E = 10 keV, the required focusing resolution is 10 nm, and the focal length is selected as 4 mm, the total film thickness should be 10 μm. Based on the coating capability and resolution requirements, the outermost layer thickness is selected as 3 nm. According to calculations, the total number of film layers is 13750.

[0054] As a possible implementation, for 80% of all the said functional membrane layers 1... Perform linear fitting.

[0055] To verify that the function of the multilayer Laue lens with linear gradient of functional film 1 in this scheme can completely replace the multilayer Laue lens with polynomial gradient of functional film 1, a theoretical verification of the multilayer Laue lens with linear gradient of functional film 1 in this scheme is carried out.

[0056] Using the Takagi-Taupin theory, the diffraction curve η-1(z) of the negative 1st order diffraction efficiency as a function of depth z was calculated.

[0057] Based on the diffraction curve η-1(z), the optimal depth Zopt = 10 μm is selected to maximize efficiency;

[0058] Based on the optimal depth Zopt, the electric field distribution on the outgoing surface is calculated. Using Kirchhoff-Fresnel diffraction integrals, the light intensity distribution on the image plane is obtained, and the focusing resolution of the multilayer Laue lens is 8 nm.

[0059] Based on the above theoretical verification, a one-dimensional focusing comparison image was obtained between the multilayer Laue lens with a linearly varying gradient of functional layer 1 in this scheme and the wedge-shaped multilayer Laue lens with a polynomially varying gradient of functional layer 1 in the prior art, as shown in the image. Figure 3 As shown; and, a comparison diagram of the intensity distribution near the focal point when focusing is achieved between the multilayer Laue lens in this scheme, where the gradient of the functional film layer 1 varies linearly, and the wedge-shaped multilayer Laue lens in the prior art, where the gradient of the functional film layer 1 varies polynomially. Figure 4 As shown.

[0060] Depend on Figure 3 It can be seen that the intensity distribution of the multilayer Laue lens with a linear gradient of functional film layer 1 in this scheme is similar to that of the wedge-shaped multilayer Laue lens with a polynomial gradient of functional film layer in the prior art, and at the focal length... f (8nm), and double the focal length 2 f The intensity is highest at 16 nm. Curve C represents the intensity distribution curve of a wedge-shaped multilayer Laue lens where the gradient of the functional film layer exhibits a polynomial relationship, while curve D represents the intensity distribution curve of a multilayer Laue lens where the gradient of the functional film layer in this scheme exhibits a linear relationship. Furthermore, Figure 4(a) shows the intensity distribution near the focal point of a wedge-shaped multilayer Laue lens in the prior art where the gradient of the functional film layer 1 changes in a polynomial relationship when focusing is achieved. (b) shows the intensity distribution near the focal point of a multilayer Laue lens in the present solution where the gradient of the functional film layer 1 changes in a linear relationship when focusing is achieved. It is easy to see from the figure that the intensity distributions of the two are almost the same and the intensity difference is small. The multilayer Laue lens in the present solution where the gradient of the functional film layer 1 changes in a linear relationship can completely replace the wedge-shaped multilayer Laue lens in the prior art where the gradient of the functional film layer 1 changes in a polynomial relationship when focusing, while greatly reducing the manufacturing difficulty.

[0061] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0062] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A multilayer Laue lens, comprising multiple functional film layers stacked together, each functional film layer being inclined relative to the light transmission axis of the multilayer Laue lens, each functional film layer comprising an absorption layer and a spacer layer stacked together, the absorption layer and the spacer layer of adjacent functional film layers being alternately arranged; characterized in that, The gradient of the functional membrane layer varies linearly within at least a portion of the layer count range. The gradients of each of the functional membrane layers within at least a certain number of layers are obtained in the following manner: ； ； ； For each of the functional membrane layers within a predetermined number of layers Perform linear fitting to obtain the gradient; in, The number of functional film layers in the multilayer Laue lens from thickest to thinnest direction. For the first The position radius of the functional film layer described above. The operating wavelength of the multilayer Laue lens is [not specified]. The focal length of the multilayer Laue lens is... For the first The thickness of the functional film layer described above, , where represents the theoretical gradient value of each of the functional membranes that are not linearly fitted.

2. The multilayer Laue lens according to claim 1, characterized in that, The absorber layer and the spacer layer in the same functional membrane layer have the same thickness.

3. The multilayer Laue lens according to claim 1, characterized in that, The absorber layer is made of at least one of WSi2 and Nb, and the spacer layer is made of at least one of Si and Al.

4. The multilayer Laue lens according to claim 1, characterized in that, The maximum number of functional layers N of the multilayer Laue lens is determined according to the following relationship; ； in, The thickness of the Nth functional film layer; The thickness of the outermost absorption layer or the spacer layer.

5. The multilayer Laue lens according to claim 1, characterized in that, For more than 70% of all the aforementioned functional film layers Perform linear fitting.

6. The multilayer Laue lens according to claim 5, characterized in that, The functional film layer from the predetermined layer to the outermost functional film layer Perform linear fitting.

7. The multilayer Laue lens according to claim 5 or 6, characterized in that, For 80% of all the aforementioned functional membrane layers Perform linear fitting.

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